Our primary purpose is to examine pathophysiological aspects of the coronary-prone Type A behavior pattern in families. The physiological data and some of the behavioral data will be based on the Family Heart Study (FHS), which consists of 403 families (821 adults, 18-70 years of age, and 267 children, 6-17 years of age). The proposed projects, which are not part of the goals of the FHS, will address three issues. First, familial aggregation of Type A behavior and other coronary risk factors (plasma lipoprotein, lipids, systolic and diastolic blood pressure, heart rate, smoking, and obesity) will be examined longitudinally. Second, possible mechanisms linking Type A behavior to coronary heart disease will be investigated by examining the relationship of Type A behavior and life stress to smoking as well as to physiological coronary risk factors. Finally, behavioral correlates (Type A, smoking) of week-to-week intra-individual variability in physiological coronary risk factors will be examined in adults and children. We will employ multivariate analyses, repeated measure designs, and intraclass analyses where the relationships of variables within families are concerned. In addition to adding to our understanding of environmental, physiological and bahavioral factors related to increased CHD risk and to increased intraindividual physiological and metabolic variability, information derived from the proposed project will add to our understanding of developmental aspects of Type A behavior an other coronary risk factors in children and their families. Also, information on CHD risk in our sample of relatively young families (274 of the adults in the sample are between the ages of 18 and 30 years) will contribute to filling the gap in our knowledge of CHD risk in young adults. The results of the above research could be potentially useful in the design of individualized cardiovascular risk factor reduction programs and identifying families at high risk for coronary heart disease.